Film-shaped adhesive application apparatus

ABSTRACT

A film-shaped adhesive application apparatus includes a supply reel retainer for mounting a film-shaped adhesive supply reel used to wind into a roll shape a film-shaped adhesive  1  comprising a base film and an adhesive layer formed thereon, thermocompression bonding means for thermocompression-bonding the film-shaped adhesive drawn from the film-shaped adhesive supply reel to an adherend, and a winding reel retainer for mounting a winding reel used to wind the base film of the thermocompression-bonded film-shaped adhesive, and further temperature control means (thermal shield plate, cooler, or the like) for controlling the film-shaped adhesive supply reel mounted on the supply reel retainer at a prescribed temperature.

[0001] BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a film-shaped adhesiveapplication apparatus for thermocompression-bonding a film-shapedadhesive to a substrate or other such adherend using a film-shapedadhesive supply reel on which the film-shaped adhesive is wound into aroll shape.

[0004] 2. Description of the Related Art

[0005] Anisotropic conductive films (ACF) are widely used in LCDperipheral mounting, and have recently also been employed in COF (Chipon Film), COB (Chip on Board), and other such bare chip mounting.

[0006] As shown in FIGS. 2A and 2B , an anisotropic conductive film 1 atypically comprises an anisotropic conductive adhesive layer 3 and acover film 4 laminated as needed on top of a base film 2, and employingthis in bare chip mounting necessitates the use of an anisotropicconductive. film supply reel 5 a in which the anisotropic conductivefilm 1 a is wound into a roll shape.

[0007] As shown in FIG. 4, an application apparatus 10 is employed as anapparatus for temporarily tacking an anisotropic conductive film 1 a ina continuous manner to a substrate 30 using the anisotropic conductivefilm supply reel 5 a. This apparatus 10 comprises a supply reel retainer11 for mounting the anisotropic conductive film supply reel 5 a, a stage12 for mounting the substrate 30 thereon, cover film winding means forseparating a cover film 4 from the anisotropic conductive film 1 adrawnfrom the anisotropic conductive film supply reel 5 a and winding thecover film on a cover film winding reel 13, film cutting means 14 forfully cutting or half-cutting to a prescribed length the anisotropicconductive film 1 a from which the cover film 4 has been separated, athermocompression bonding roller 15 for thermocompression-bonding thefully cut or half-cut anisotropic conductive film 1 a to the substrate30 and transferring and affixing the anisotropic conductive adhesivelayer 3 to the substrate 30, and a winding reel retainer 17 for mountinga winding reel 16 used to wind the base film 2 after the anisotropicconductive adhesive layer 3 is transferred and affixed.

[0008] However, as the anisotropic conductive film 1 a is drawn from theanisotropic conductive film supply reel 5 a in the conventionalapplication apparatus 10, the anisotropic conductive film 1 a issometimes wound tightly inside the anisotropic conductive film supplyreel 5 a, the anisotropic conductive adhesive layer 3 is squeezed outfrom the side of the anisotropic conductive film 1 a as in FIG. 5,blocking occurs between the anisotropic conductive films 1 a during thetacking operation, making it impossible to smoothly draw the anisotropicconductive film 1 a and causing the application apparatus 10 to stop.Productivity suffers as a result.

SUMMARY OF THE INVENTION

[0009] Therefore, an object of the present invention is to provide anapplication apparatus that prevents squeeze-out or blocking of anadhesive layer on a film-shaped adhesive supply reel on which ananisotropic conductive film or other such film-shaped adhesive is woundinto a roll shape, and enables a film-shaped adhesive to be continuouslyapplied.

[0010] The inventors have discovered that controlling the interior of afilm-shaped adhesive supply reel at a prescribed temperature bythermally shielding the film-shaped adhesive supply reel from athermocompression bonding roller or other such heat source or by coolingthe film-shaped adhesive supply reel with a spot cooler or the likemakes it possible to prevent squeeze-out or blocking of an adhesivelayer on the film-shaped adhesive supply reel.

[0011] Specifically, the present invention provides a film-shapedadhesive application apparatus comprising a supply reel retainer formounting a film-shaped adhesive supply reel used to wind into a rollshape a film-shaped adhesive comprising a base film and an adhesivelayer formed thereon, thermocompression bonding means forthermocompression-bonding the film-shaped adhesive drawn from thefilm-shaped adhesive supply reel onto an adherend, and a winding reelretainer for mounting a winding reel used to wind the base film of thethermocompression-bonded film-shaped adhesive; wherein the applicationapparatus further comprises temperature control means for controllingthe film-shaped adhesive supply reel mounted on the supply reel retainerat a prescribed temperature.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a schematic depicting the film-shaped adhesiveapplication apparatus of the present invention;

[0013]FIGS. 2A and 2b are a side view (a) and an expanded fragmentaryview (b) of a reel of an anisotropic conductive film, respectively;

[0014]FIG. 3 is a diagram depicting the relation between the ambienttemperature of the reel and the extent to which the adhesive layer issqueezed out;

[0015]FIG. 4 is a schematic depicting a conventional film-shapedadhesive application apparatus; and

[0016]FIG. 5 is a side view of a film-shaped adhesive in which theanisotropic conductive adhesive layer is squeezed out due to rolltightening within the reel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The present invention is described in detail below with referenceto diagrams. In each diagram, identical symbols indicate identical orsimilar structural elements.

[0018]FIG. 1 is a schematic depicting the film-shaped adhesiveapplication apparatus 10A of an embodiment of the present invention.This application apparatus 10A comprises a supply reel retainer 11 formounting a film-shaped adhesive supply reel 5 in which a film-shapedadhesive 1 is wound into a roll shape, a stage 12 for mounting asubstrate 30 or other such adherend thereon, a cover film winding reel13 for separating a cover film 4 from the film-shaped adhesive 1 drawnfrom the film-shaped adhesive supply reel 5 and winding the separatedcover film 4, film cutting means 14 for fully cutting or half-cutting toa prescribed length the film-shaped adhesive 1 after the cover film 4has been separated, thermocompression bonding means 18 forthermocompression-bonding the film-shaped adhesive 1 to the adherend,and a winding reel retainer 17 for mounting the winding reel 16 used towind the base film 2 of the thermocompression-bonded film-shapedadhesive 1.

[0019] Examples of the film-shaped adhesive 1 include an anisotropicconductive adhesive film 1 a that comprises at least an anisotropicconductive adhesive film layer comprising a base film and an anisotropicconductive adhesive layer laminated on the base film and that mayfurther comprises, if necessary, a cover film laminated on theanisotropic conductive adhesive layer, an insulating adhesive film thatcomprises a base film and an insulating adhesive layer laminated on thebase film, an insulating adhesive film that further comprises a coverfilm laminated on the insulating adhesive layer as needed, and so on.

[0020] The supply reel retainer 11, the stage 12, the film cutting means14, the thermocompression bonding means 18, and the winding reelretainer 17 may all be identical to widely known applicationapparatuses. For example, the thermocompression bonding means 18 may bea thermocompression bonding roller 15, thermocompression bonding head,or other component in which the thermocompression bonding surface can becontrolled at 70-1 50° C. and the adherend can be heated and pressedwhile moved in the direction of the arrow.

[0021] A thermal shield plate 19 for thermally shielding the film-shapedadhesive supply reel 5 mounted on the supply reel retainer 11 from thethermocompression bonding means 18 is provided to the applicationapparatus 10A so as to enclose the film-shaped adhesive supply reel 5mounted on the supply reel retainer 11. Plastic material is preferablyused as the structural material for the thermal shield plate 19 becauseof the low thermal conductivity thereof. Thus, the thermal shield plate19 acts as a temperature control means for controlling the film-shapedadhesive supply reel 5 mounted on the supply reel retainer 11 at aprescribed temperature. Specifically, when the film-shaped adhesive 1 iscontinuously applied by thermocompression bonding to an adherend, theheat from the thermocompression bonding means 18 is prevented fromspreading to the film-shaped adhesive supply reel 5, and the film-shapedadhesive 1 is maintained at a temperature at which the adhesive layerconstituting the film-shaped adhesive 1 in the film-shaped adhesivesupply reel 5 assumes a hardness level sufficient to prevent theadhesive from being squeezed out even when the roll is tightened by theunwinding action of the film-shaped adhesive supply reel 5. Morespecifically, for example, when the adhesive layer constituting thefilm-shaped adhesive 1 comprises a epoxy resin or other suchthermosetting resin and the 70-150° C. thermocompression bondingoperations of the thermocompression bonding means 18 are performedcontinuously at room temperature, structuring the thermal shield plate19 from a polycarbonate allows the film-shaped adhesive 1 in thefilm-shaped adhesive supply reel 5 to be maintained at 30° C. or less.

[0022] A spot cooler or other such cooler for cooling the film-shapedadhesive supply reel 5 by blowing cold air on the film-shaped adhesivesupply reel 5 mounted on the supply reel retainer 11 may be provided tothe application apparatus of the present invention as a temperaturecontrol means in place of the previously described thermal shield plate19 or together with the previously described thermal shield plate 19.When the film-shaped adhesive supply reel 5 is actively cooled by thecooler, overcooling results in condensation on the surface of thefilm-shaped adhesive 1 and causes the film-shaped adhesives 1 to clingto each other, hindering the application apparatus in its ability tooperate in a continuous manner. Therefore, the cooling action of thecooler is appropriately regulated so as not to cause such condensation.

[0023] As a temperature control means, the shaft on which thefilm-shaped adhesive supply reel 5 is mounted in the supply reelretainer 11 may serve as a cooling shaft, allowing the film-shapedadhesive supply reel 5 mounted on the supply reel retainer 11 to becooled from the side of the winding core of the film-shaped adhesivesupply reel 5. A specific structure of the cooling shaft may, forexample, be such that the shaft on which the film-shaped adhesive supplyreel 5 is mounted is cooled by cooling water, coolant gas, or the like.The temperature can thereby be controlled efficiently.

[0024] The application apparatus 10A of the present invention can beembodied in a variety of ways according to the layer structure and thelike of the film-shaped adhesive. For example, the cover film windingreel 13 or other such cover film winding means can be dispensed with inthe case of film-shaped adhesives with no cover film.

EXAMPLES Examples 1-6, Comparative Example 1

[0025] An anisotropic conductive film supply reel (width 5 mm, 50-metercoil) (CP7131, Sony Chemicals Corp.), on which an anisotropic conductivefilm (cover film thickness 25 μm, adhesive layer thickness 25 μm, basefilm thickness 50 μm) was wound into a roll shape, was mounted such thatthe reel tension of the anisotropic conductive film was 100 g, and theanisotropic conductive adhesive layer thereof was continuouslythermocompression-bonded to a glass substrate with a thermocompressionbonding roll (100° C.) over the entire length of a 50-meter film. Inexamples 1-6, the ambient temperature of the reel was controlled asshown in Table 1 by installing a spot cooler within a thermal shieldplate composed of a polycarbonate material and regulating the airflow.In Comparative Example 1, neither a thermal shield plate nor a spotcooler was installed.

[0026] Evaluation

[0027] (1) Extent to which adhesive layer was squeezed out: Immediatelybefore completion of the continuous thermocompression bonding, theaverage value of the extent to which the anisotropic conductive adhesivelayer was squeezed out on the side of the anisotropic conductive filmwas calculated by observing the anisotropic conductive film remaining onthe film-shaped adhesive supply reel and measuring the film with amicrometer.

[0028] (2) Blocking: Immediately before completion of the continuousthermocompression bonding, the occurrence of blocking of the anisotropicconductive film remaining on the film-shaped adhesive supply reel wasascertained. No blocking was indicated by “G”, and blocking wasindicated by “NG ”.

[0029] (3) Condensation: During continuous thermocompression bonding,the occurrence of condensation was ascertained by observing (with thenaked eye) the surface of the anisotropic conductive film wound on thefilm-shaped adhesive supply reel. No condensation was indicated by a“G”, and condensation was indicated by “NG”.

[0030] (4) Continuous operability: During continuous thermocompressionbonding of the entire 50-meter film, no

[0031] 5 instances of apparatus shutdown was indicated by “A”, less thanten instances of apparatus shutdowns was indicated by “B”, and ten ormore instances of apparatus shutdown was indicated by “C” amultiplication sign.

[0032] These results are shown in Table 1. FIG. 3 depicts therelationship between the ambient temperature of the film-shaped adhesivesupply reel and the extent to which the adhesive layer was squeezed out.

[0033] These results show that controlling the temperature of thefilm-shaped adhesive supply reel makes it possible to reduce the extentto which the adhesive layer is squeezed out, to prevent blocking, and tocontinuously operate the application apparatus. TABLE 1 Squeeze-Condensa- Continuous Temp. (° C.) out (μm) Blocking tion operability Ex.1 30 11 G G A Ex. 2 25 8 G G A Ex. 3 20 6 G G A Ex. 4 15 4 G G A Ex. 510 3 G G A Ex. 6  5 2 G NG B Com. 23→35 (*1) 19 NG G C Ex. 1

[0034] By using the film-shaped adhesive application apparatus of thepresent invention, the film-shaped adhesive can be prevented from beingblocked, or the adhesive layer can be prevented from being squeezed outdue to roll tightening of the film-shaped adhesive supply reel on whichthe film-shaped adhesive is wound, and the film-shaped adhesive cantherefore be continuously applied.

[0035] The entire disclosure of the specification, claims, summary anddrawings of Japanese Patent Application No. 2002-083288 filed on Mar.25, 2002 is hereby incorporated by reference.

What is claimed is:
 1. A film-shaped adhesive application apparatus,comprising a supply reel retainer for mounting a film-shaped adhesivesupply reel used to wind into a roll shape a film-shaped adhesivecomposed of a base film and an adhesive layer formed thereon,thermocompression bonding means for thermocompression-bonding thefilm-shaped adhesive drawn from the film-shaped adhesive supply reelonto an adherend, and a winding reel retainer for mounting a windingreel used to wind the base film of the thermocompression-bondedfilm-shaped adhesive; wherein the application apparatus furthercomprises temperature control means for controlling the film-shapedadhesive supply reel mounted on the supply reel retainer at a prescribedtemperature.
 2. The application apparatus according to claim 1, whereinthe temperature control means controls the film-shaped adhesive supplyreel mounted on the supply reel retainer at 10-30° C.
 3. The applicationapparatus according to claim 1 or 2, wherein the temperature controlmeans comprises a thermal shield plate for thermally shielding thefilm-shaped adhesive supply reel mounted on the supply reel retainerfrom the thermocompression bonding means.
 4. The application apparatusaccording to claim 1 or 2 wherein the temperature control meanscomprises a cooler for blowing cold air on the film-shaped adhesivesupply reel mounted on the supply reel retainer.
 5. The applicationapparatus according to claim 1 or 2, wherein the temperature controlmeans comprises a cooling shaft of the supply reel retainer for coolingthe film-shaped adhesive supply reel mounted on the supply reel retainerfrom the winding core side of the reel.